As is well-known in the processing of photographic materials seasoning of the processing solutions makes their compositions differ from the compositions of solutions added freshly to processing tanks of developer and fixer. Therefore as an efficient measure in order to minimize differences in compositions between start and while running processing, the use of starter solutions is well-known since quite a long time as has e.g. been illustrated in U.S. Pat. No. 3,276,874. More recently in EP-A 0 696 759 a method for processing a black-and-white silver halide photographic material in an automatic processing machine or processor is disclosed, wherein the developer replenisher is used in the form of a concentrated solution or in the form of a solid comprising a dihydroxybenzene or ascorbic or erythorbic acid or derivatives thereof.
A developer replenisher having a higher pH value (in an amount of at least 0.5) than its development starting solution has been described in U.S. Pat. No. 5,503,965. Addition of starter, including at least one alkali agent, to the fixer in order to have a difference of pH between new liquid and running liquid within 0.2 has been described for a fixer having a pH after adding starter from 4.0 to 5.0 as in JP-A 03-68937, whereas a pH from 4.3 to 5.3 is controlled in JP-A 06-250350. Replenishing fixer solutions having a higher thiosulphate concentration than in the fixer at the start of processing, wherein pH of the fixer is more than 3.8 and preferably from 4.2-5.5 has been described in JP-A 06-230527, for rapid processing applications. Starter tablets have further been described in JP-A 04-032839.
The addition of sulfite salts to the fixer replenisher solution is known in order to compensate for the drop in sulphite concentration and pH decrease due to electrolysis. Electrolysis can proceed for example by passing the fixer around a circulation loop which includes an electrolytic cell. Electrolytic removal of silver also has the benefit of enabling a lower regeneration rate of fixer to be used. This is fully consistent with recent trends to reduce the volume of treatment liquids used in photographic processing. Electrolysis of the fixer solution, known as most efficient method of chemical recovery of the said fixer solution in order to reduce the slow down effect on fixation rate of increasing amounts of silver ions present in the fixer, however makes pH and sulfite ion concentration decrease.
As a consequence a less stable fixer solution is provided, wherein sulfur deposit may tend to occur as has e.g. been described in J.Imag.Techn. Vol. 10 (1984), p. 214 and in Materials Evaluation, April 1991, p. 511.
As an approach of modern technological developments related with rapid processing from the viewpoint of ecology is becoming more and more stringent, a demand for lower replenisher volumes is a normal trade-off. As a consequence differences in compositions between seasoned processing solutions and fresh solutions after throughput of constant amounts of photographic material tend to increase. The said differences are the ultimate factors determining to what extent reduction in replenishing amounts may be carried out.
Problems resulting therefrom are e.g. lack for constant and acceptable sensitometric properties (a "must" with respect to "constant quality" required by the clients), degradation of physical properties (e.g. uneven gloss at the surface of the processed and dried material) and unacceptable odour of the processing solutions.